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W. M. GRISGOM.

ROTARY ENGINE.

No. 408,101. Patented July 30, 1889.

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UNITED STATES PATENT OFFICE.

WILLIAM M. GRISCOM, OF BERLIN, GERMANY.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 408,101, dated July 30, 1889.

To all whom it may concern:

Beit known that 1, WILLIAM M. GRISCOM, a citizen of the United States, and aresident of Berlin, Germany, have invented certain Improvements in Rotary Engines, of which the following is a specification.

My invention consists of certain improvements in that class of engines in which a cylinder pivoted eccentrically in respect to an annular track is provided with a piston and piston-rod, the latter carrying at its outer end anti-friction rollers adapted to said annular track, the object of my invention being to provide such an engine with valve mechanism of a more acceptable character than has heretofore been employed in connection with engines of this class. This object I attain in the manner hereinafter set forth, reference being had to the accompanying drawings, in which- Figure 1 represents in longitudinal section an engine constructed in accordance with my invention; and Fig. 2 is a transverse section, on a smaller'scale, on the line 1 2, Fig. 1.

A represents the fixed frame of the engine, forming part of which is an annular track or guide, which, in the present instance, is duplex-that is to say, it comprises an inner part B, formed in one piece with the fixed frame, and an outer part B, in the form of a ring bolted or otherwise securely fastened to a flange on the inner part B. To a bearing a 0n the fixed frame, eccentrically disposed with reference to the axis of the annular track or guide, is adapted a hollow shaft or trunnion D, which is secured to or forms part of the cylinder F of the engine, the latter having at one side a steam-chest F of ordinary construction, and the cover of this steamchest having a trunnion D, adapted to a bearing a in the fixed frame A, which is mounted adjacent to the fixed frame A. The piston 19 of the cylinder has a rod 1), which passes through a stuffing-box at each end of the cylinder, so that the same area of piston is exposed on each side to the pressure of steam; hence the engine will be balanced and both impulses imparted to the piston will be alike. One end of the piston-rod is provided with a head d, carrying the spindle e of a pair of anti-friction rollers fione of which is adapted to the portion B of the annular track or guide and the other to the corresponding portion B of the same. As the annular track or guide is fixed and the cylinder F is eccentrically pivoted in respect thereto, it follows that the reciprocating movement of the piston 1), its rod, and the anti-friction rollers carried thereby will cause a rotating movement of the cylinder F, the piston being at one end of its stroke when the rollers are traversing that part of the annular track which is at the greatest distance from the axis of the cylinder, and at the opposite end of the stroke when the rollers are traversing that portion of the track at the least distance from said axis. During one stroke the rollers bear upon the outer face of the annular track, and during the other stroke the rollers bear upon the inner face of the track, there being avery slight play of the rollers between the two faces, so as to prevent them from bearing upon the faces simultaneously at any point.

Engines of this character as heretofore constructed have generally been provided with valves in the hollow shafts or trunnions; but such valves are objectionable on account of their comparative inaccessibility and the difficulty of compensating for wear of the parts and preventing leakage. I therefore in my improved engine use an ordinary form of slide-valve G in connection with inlet and exhaust ports, such as are used in stationary engines of the ordinary type, and I operate the slide-valve by a supplementary annular track H H, in all substantial respects similar to the annular track B B, with which engage the rollers 011 the piston-rod of the engine, the valve-rod G having similar rollers f, the spindle e of which is carried by a head d on the valve-rod, the latter passing through stuffing-boxes at the opposite ends of the valve-chest, so that as the cylinder rotates the valve G will, owing to the eccentric character of the track or guide H H, be caused to move to and fro over the valve-seat, so as to provide for the inlet and exhaust of steam at the opposite ends of the cylinder in the usual manner. The valve-controlling track or guide H H, however, is not secured in a fixed position on the fixed frame A of the engine, but is free to turn thereon to the extent of a halfrevolution, so as to effect such a movement of the valve Gas will reverse the engine. This movement may be effected by means of a lever applied directly to the annular track or guide, although in order to avoid the extended movement of the reversinglever, which would be required in this case, it is preferable to form on the hub of the ring l-I an annular or segmental rack m for engagement with a sliding rack 01, connected to the reversing-lever, as shown in Fig. 2, for instance, a reciprocating movement of this rack to the proper extent effecting the turning of the ring H, so as to cause a reversal in position of the valve G.

The trunnion D of the cylinder is hollow, so as to provide for the admission of steam to the valve-chest F from a supply-pipe J,Which passes through a stuffing-box J at the outer end of the trunnion D, and is held in position by a clamp-bracket p on the fixed portion A of the frame. The trunnionD of the cylinder is likewise hollow and communicates with the exhaust-passage a: of the cylinder, the outer end of said trunnion having a stuffing-box K for the reception of the end of the exhaust-pipe K, which may beheld in position by a clamp-bracket secured to the fixed portion A of the frame, or in any other convenient way.

Although I have described and shown a duplex annular track or guide for the rollers of the piston-rod and valve-rod, and although I prefer to use this construction in all cases, yet the essential features of my invention may, as will be evident, be embodied in an engine in which but a single annular track or guide and a single roller on the piston-rod or valve-rod are employed.

Having thus described my invention, I claim and desire to secure by Letters Patent- 1. The combination of the annular track or guide, a cylinder hung eccentrically in respect thereto and having a piston and pistonrod, with rollers engaging said annular track or guide, a slide-valve for controlling the flow of the motive fluid to and from the cyl-.

inder, and a supplementary eccentric track or guide for effecting the operation of the slide-valve as the cylinder rotates, substantially as specified.

2. The combinationof the cylinder, its opposite hollow trunnions, valve-chest, and slide-valve, the fixed frame of the engine having bearings for said trunnions, the eccentric tracks or guides for controlling the outer ends of the piston-rod and valve-rod, a steam-inlet pipe communicating with the steam-chest of the engine through one hollow trunnion, and an exhaust-pipe communicating with the exhaust-passage of the engine through the other hollow trunnion, substantially as specified.

3. The combination of the cylinder, its valve-chest and slide-valve, the eccentric track or guide controlling the piston-rod of thecylinder, and an eccentric track or guide controlling the valve-rod, said valve-controlling track or guide being movable to effect the shifting of the valve and the reversal of the engine, substantially as specified.

In testimony'whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM M. ,GRISCOM.

Witnesses:

WILLIAM D. CONNER, HARRY SMITH. 

